li a {
    color: green;
}

body {
    margin: 0;
    position: relative;
    min-height: 100vh;
    background-color: white;
}

body::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url("images/background.png") no-repeat;
    background-size: contain;
    background-position: center;
    opacity: 0.5; /* 淡化 */
    backdrop-filter: blur(2px); /* 模糊（可选，数值越大越模糊） */
    z-index: -1;
}